JP2019521857A - Metal wire feeding system and method - Google Patents

Abstract

Continuously providing metal wire to a welding torch for manufacturing an object, in particular an object made of titanium or titanium alloy wire, by three-dimensional free-form shaping to perform continuous deposition of metal on the free-form object A wire delivery system and method for providing an image are provided. The system includes a wire supply spool (50), a housing with an entry wire position detector (110), a wire feeder (200), at least three slack wire guides (300, 400, 500), A slack wire tensioning device (600) and a housing withdrawal guide (1000) are provided.

Description

  The present invention relates to a system and method for delivering metal wires for producing objects, in particular objects made from titanium and titanium alloy wires, by means of three-dimensional freeform shaping.

  Structured metal parts made of titanium or titanium alloys are conventionally made by casting, forging or machining from billets. These techniques have the disadvantages of expensive material waste of titanium metal and long lead times in the fabrication of metal parts.

  A sufficiently dense physical object may be made by manufacturing techniques known as high speed prototyping, high speed manufacturing methods, layered manufacturing methods, three-dimensional freeform modeling methods, additive modeling methods, additive manufacturing methods, or 3D printing. This technology uses computer-aided design software (CAD) to first build a virtual model of the object to be created, and then convert the virtual model into thin parallel slices or layers that are normally oriented horizontally To do. Thereafter, the physical object may be in the form of a liquid, paste, powder, or other stackable, spreadable, or fluid form continuous material, such as from molten metal, such as molten metal. It may also be made by stacking successive layers of raw material preformed as a sheet material similar to the shape of the layer or virtual layer until the entire object is formed. The layers are fused together to form a three-dimensional dense object.

  Three-dimensional freeform modeling is a flexible technique that allows the creation of objects of almost any shape at a relatively high production rate, typically in the range of hours to days, for each object. Therefore, this technique is suitable for the formation of prototypes and continuous production in small quantities, and can be scaled up for mass production.

  Laminate manufacturing techniques may be extended to include the deposition of multiple pieces of constituent materials, ie, a set of parts that form layers when each structural layer of a virtual model of an object is placed side by side Divided into pieces. This makes it possible to weld metal objects by welding the wire onto the substrate in a continuous stripe form forming each layer according to a virtual stacking model of the object, and repeating the process for each layer until the entire physical object is formed. Can be formed. The accuracy of welding techniques is usually so coarse that an object of acceptable dimensions cannot be directly formed. Thus, the object to be formed is usually considered a raw object or preform that needs to be machined to an acceptable dimensional accuracy.

  It is known to use a plasma arc to provide heat for welding metal materials. This method may be used at atmospheric or higher pressures and thus provides a simpler and less expensive process equipment. One such method is known as gas tungsten arc welding (also referred to as GTAW, TIG welding) in which a plasma transfer arc is formed between a non-consumable tungsten electrode and a weld region. The plasma arc is usually protected by a gas that is delivered through a plasma torch and forms a protective gas shield around the arc. TIG welding can include feeding metal wire or metal powder as a filler material into a molten pool or into a plasma arc. Other welding methods include gas metal arc welding (GMAW), metal inert gas (MIG) welding, and metal active gas (MAG) welding, in which consumable electrodes such as metal wires and workpieces are used. An electric arc between and heats and melts the metal.

  It is known to use TIG welding torches to construct objects by solid freeform shaping (SFFF) (a continuous layer of a low ductility metal feed raw material is deposited on a substrate) (eg, (See Adams (Patent Document 1)). A plasma arc is generated by exciting the flowing gas using the electrode, and a current of varying magnitude is supplied to the electrode. In order to preheat a predetermined target area of the workpiece prior to deposition, the plasma stream can be directed to the predetermined target area. As the current is adjusted, the feedstock is delivered to the plasma stream and the molten feedstock is deposited in a predetermined target area. As the current is adjusted, the molten feedstock is gradually cooled to a high temperature (typically above the brittle-ductile transition temperature of the feedstock), minimizing the generation of material stress during the cooling phase. .

  Withers et al. (Patent Document 2) also uses a relatively low cost titanium feed by combining a titanium feed and an alloying component in a manner that significantly reduces the cost of the raw material, in a three-dimensional freeform fabrication (SFFF) process. It describes the use of a TIG torch instead of the expensive lasers conventionally used. More particularly, in one aspect, the present invention uses a pure titanium wire (CP Ti wire) that is less costly than an alloy wire and uses a CP Ti wire and powder alloy in melting a welding torch or other high power energy beam. By combining the alloying component, the CP Ti wire is combined with the powder alloying component as it is in the SFFF process. In another embodiment, the present invention is a titanium sponge material that is mixed with alloying elements and formed into a wire, which is a plasma welding torch or other high power to produce titanium near net shape components. A titanium sponge material that can be used in the SFFF process in combination with an energy beam is used.

  In order to effectively deposit metal from the metal wire onto the surface of the workpiece using the welding torch, it is necessary to maintain the metal wire in the correct position relative to the welding torch. Metal wires are often supplied from a spool. The output torque of the motor that drives the rotation of the wire spool can be a limiting factor in providing the wire in a steady state, particularly from a full spool. The rotational inertia of the wire on the spool can limit the speed and acceleration at which the wire can be unwound from the spool for delivery to the welding torch. The modulation of rotational inertia, speed and / or acceleration may be sufficient to cause slippage from the roller, guide wheel or clamping device used to deliver the wire to the plasma arc of the contact tip assembly. There is. Slip causes deformation in the wire and can cause a shift in the desired position and angle of the wire relative to the plasma arc. Slip also limits the operating speed of the modeling equipment.

  Changes in the rotational mass, speed and / or acceleration of the bulk wire can also result in variations in wire feed speed and variations in the amount of tension in the metal wire. If variations in wire feed speed or wire acceleration at the wire source result in excessive tension between the feed roller and pulley that delivers the wire to the plasma arc of the welding torch and the wire source, the increased tension causes the wire to Twists, bends or other deformations can be formed. Also, the high tension can cause the metal wire to be pulled back towards the wire source, which prevents the metal wire from being fed to the welding electrode and in a layer deposited on the freeform object being made, Undesirable discontinuous deposition layers or unintended holes or gaps are produced. If the tension is too low, extra slack can occur. The extra wire can be intertwined with the wire itself or part of the machinery, which can cause the wire to bend or twist, making it difficult or impossible to properly position the wire with respect to the plasma arc. It becomes possible.

  In addition, unwinding the wire from the spool can cause a change in the position of the wire as it leaves the spool due to the coiled nature of the wire on the spool. At higher utilization rates, the horizontal and vertical position of the wire can change rapidly, and this change can cause slippage from the rollers, guide wheels or clamping devices used to deliver the wire to the welding torch. There is a possibility to bring.

US Patent Application Publication No. 2010/0193480 US Patent Application Publication No. 2006/185473

  Thus, there is a need in the art for an economical method of freeform shaping at an increased metal deposition rate. Furthermore, there is a system and method in the art that increases the amount of metal wire that can be provided to the welding torch without slipping or deformation of the metal wire to improve the throughput and yield of products formed by direct metal deposition. is necessary.

  An object of the present invention is to provide a system for delivery of a metal wire to a welding torch for constructing a metal object by solid freeform shaping.

  Another object of the present invention is to provide a method for high speed laminate manufacturing of titanium bodies or titanium alloy bodies using metal wires and one or more welding torches. The present invention provides a system and method for delivering a metal wire to a plasma arc of a welding torch at a desired location with respect to the plasma arc, and the need for an improved economic method of performing direct metal deposition. This can lead to an increased metal deposition rate in 3D freeform shaping. The present invention further addresses the need for a method to increase throughput, and can produce parts formed by unstrained direct metal deposition with near net shape smooth deposition boundaries.

  The innovation provides a metal wire delivery system for accepting metal wires from a wire source and delivering wires to be used in a 3D freeform shaping system. The system includes a housing that accepts a metal wire from a wire source, a positioning sensor that monitors the position of the wire that enters the housing from the wire source, and a wire from the wire source to form a slack wire loop in the housing. A wire feeder that is advanced into the body, one or more sensors that detect and modulate the amount of slack wire in the housing, and a predetermined to the welding torch for melting on the surface of the workpiece. And a wire providing device that pulls and provides a wire guide with an amount of slack wire to be positioned in position. The welding torch can have any suitable design or configuration. Exemplary welding torches include plasma arc welding torches, plasma transfer arc welding torches, gas tungsten arc welding torches, gas metal arc welding torches, metal inert gas welding torches, metal active gas welding torches, laser devices, and electron beam guns. , And any combination thereof.

  The wire delivery system provided herein modulates the amount of additional wire delivered from the wire source into the housing, thereby reducing the size of the slack wire loop and thus the amount of slack wire in the housing. A control system responsive to the sensor for modulating may be included.

  In this specification, it is a metal wire feeding system, Comprising: The wire supply unit containing the wire supply spool which can be adjusted, and the housing | casing which accommodates the wire tension unit for drawing a metal wire from a wire supply unit in a housing | casing A wire buffer unit that generates a loop of the slack wire as a buffer portion, and a slack wire by pulling the slack wire from the buffer loop so that the metal wire is fed to the plasma arc of the welding torch of the contact tip assembly. A metal wire delivery system is provided that can include a slack wire delivery unit that feeds the contact tip assembly out of the body.

  The housing includes an ingress wire position detector 110 that includes an opening 120 through which a metal wire 180 can pass, a motorized grooved roller 220, a passive grooved roller 205, and a motor 225 attached to the grooved roller 220. Device 200. Grooved rollers 205 and 220 can include friction enhancing surfaces. The motorized grooved roller 220 and the passive grooved roller 205 together form a path through which the metal wire 180 passes between the motorized grooved roller 220 and the passive grooved roller 205. The motorized grooved roller 220 and the passive grooved roller 205 are in frictional contact with at least a portion of the metal wire 180, and the metal wire 180 is fed to the wire buffer unit by the rotation of the motorized grooved roller 220 and the passive grooved roller 205. The

  In the metal wire delivery system provided herein, the ingress wire position detector 110 further comprises an array of sensors 122 that can detect the position of the wire 180 within the opening 120. Exemplary sensors include optical sensors, optical fiber sensors, proximity sensors, photoelectric sensors, magnetic sensors, and combinations thereof. These sensors are commercially available (see, eg, Industrial Automation-Omron Corporation, Kyoto, Japan). In some configurations, the ingress wire position detector 110 includes an array of fiber optic sensors. Sensor 122 can communicate with and provide feedback to the control system that can reposition the wire supply spool in the X, Y, or Z direction, or a combination thereof. The control system can control the orientation of the wire feed in response to feedback from the sensor 122. The housing of the system provided herein can include a transparent window or a transparent door, or both, to allow viewing of components within the housing without opening the housing. The transparent window or door can be made of glass, acrylic (poly (methyl methacrylate) or PMMA), glycol modified polyethylene terephthalate (PETG), or polycarbonate.

  In the metal wire delivery system provided herein, the wire feeder 200 can be configured to feed the wire from the wire supply spool into the housing. A wire tensioning unit 20 that includes a pressure device 800 can be included to modulate the amount of pressure (orthogonal force) exerted by the grooved roller 205 on the wire in the groove of the roller. The pressure device 800 includes a hydraulic, pneumatic, mechanical or electronically driven piston that increases the pressure applied to the grooved roller 205 when extended and reduces the pressure applied to the grooved roller 205 when contracted. Can be included. The tensioning unit 20 including the pressure device 800 modulates the amount of wire 180 fed into the housing to form a loop of the slack wire 185.

  The wire buffering unit 30 of the metal wire delivery system can include a combination of at least three wire guides. The first wire guide 300 is positioned behind the wire feeding device 200 and on a straight line with the wire feeding device 200, the second wire guide 400 is positioned at the lower right of the wire guide 300, and the third The wire guide 500 is positioned on the lower left side of the wire guide 300, and the wire guide 300 and the wire guide 500 are positioned in parallel with each other. The wire guides 300, 400 and 500 form and support a loop of the slack wire 185. In some configurations, the loop of slack wire 185 has an oval shape due to the action of gravity on the unsupported portion of slack wire 185.

  The first wire guide 300 is a double grooved roller 305 having a first groove and a second groove, and is attached to an arm 310 pivotally connected to a back plate 900 of the housing. And a double grooved roller 320 having a first groove and a second groove, wherein the first groove of the roller 305 and the first groove of the roller 320 form a channel, and The first groove can include a double grooved roller 320 that is biased by a spring on an arm 310 connected to a support 330 connected to a back plate 900.

  The second wire guide 400 is a grooved roller 405, which is a roller attached to an arm 410 pivotally connected to the back plate 900 of the housing, and a grooved roller 420, the groove of the roller 405. And the groove of the roller 420 form a channel, and the groove of the roller 405 can include a grooved roller 420 connected by a spring on the arm 410 to a support 430 connected to the back plate 900. . The third wire guide 500 is a grooved roller 505, which is a roller attached to an arm 510 pivotally connected to the back plate 900 of the housing, and a grooved roller 520, the groove of the roller 505. And the groove of the roller 520 form a channel, and the groove of the roller 505 is biased by a spring on the arm 510 connected to the support 530 connected to the back plate 900. Can be included. Wire guides 300, 400 and 500 form a loop path from wire guide 300 to wire guide 400, wire guide 500, and back to wire guide 300.

  The wire buffer unit of the metal wire delivery system provided herein can include a loop detector 700. The loop sensing device 700 can be positioned to detect at least a portion of the loop of slack wire in the housing. In some configurations, the loop sensing device 700 detects the lower portion of the loop of slack wire. The loop sensing device 700 can include one or more sensors. The loop sensing device 700 can include a sensor 730 that communicates with the control system that, when activated, sends a signal to the control system to deliver less metal wire 180 into the housing. . The loop sensing device 700 can include a sensor 720 that communicates with the control system, which when activated, sends a signal to the control system to deliver more metal wire 180 into the housing. To do. The loop sensing device 700 can include a sensor 740 that communicates with the control system, which when activated, sends a signal to the control system to stop feeding the metal wire 180 into the housing. To do. The loop sensing device 700 can include a sensor 710 that communicates with the control system, and when activated, the sensor 710 sends a signal to the control system to stop operation of the wire delivery system. The loop detection device 700 can include any combination of sensors 710, 720, 730, and 740. Other types or configurations of sensors may be used as the loop detection device 700.

  The slack wire delivery unit 40 of the metal delivery system includes a slack wire tensioning device 600 comprising a motorized grooved roller 620 and a passive (non-electric) grooved roller 605, and a motor 625 attached to the grooved roller 620. be able to. Grooved rollers 605 and 620 can include friction enhancing surfaces. The motorized grooved roller 620 and the passive grooved roller 605 together form a path through which the metal wire 180 passes between the motorized grooved roller 620 and the passive grooved roller 605. The motorized grooved roller 620 and the passive grooved roller 605 are in frictional contact with at least a portion of the slack wire 180, and the rotation of the motorized grooved roller 620 and the passive grooved roller 605 pulls the slack wire 185, leaving the chamber. Through the guide 1000, a slack wire 185 is fed out of the housing toward the plasma arc of the welding torch of the contact tip assembly.

  In the metal wire delivery system provided herein, the friction enhancing surfaces of the grooves of the rollers 220, 205, 620 and 605 can include protrusions on the surface. The friction enhancing surface of the groove can increase the friction force between the groove and the wire passing through the groove. The increased frictional force can reduce the slip between the wire and the groove. In the metal wire delivery system provided herein, the motor 225 and the motor 625 can each be a direct current motor and a stepping motor driven by output control signals.

  A slack wire delivery unit 40 including a pressure device 850 can be included to modulate the amount of pressure (orthogonal force) exerted by the grooved roller 605 on the slack wire in the groove of the roller. The pressurizing device 850 is a hydraulic, pneumatic, mechanical or electronically driven piston that increases the pressure applied to the grooved roller 605 when extended and reduces the pressure applied to the grooved roller 605 when contracted. Can be included. A motor 225 of the wire feeder 200 can be connected to the roller 220 to rotate the grooved roller 220. The motor 625 of the slack wire tensioning device 600 can be connected to the roller 620 to rotate the grooved roller 620. The motor 225 of the wire feeder 200 can be configured to operate independently of the slack wire tensioner 600.

  A method of providing a metal wire to a plasma arc of a welding torch, the step of advancing a sufficient amount of metal wire from a wire source to form a slack wire loop; A method comprising advancing from the loop to the welding torch and supplying additional metal wire from a wire source to supplement the amount of slack wire advanced to the welding torch to maintain the slack wire loop. Provided. The amount of slack wire advanced from the wire source is typically sufficient to maintain a slack wire loop to allow continuous delivery of the slack wire to the welding torch. The wire source can be an adjustable spool around which the metal wire is wound and the method unwinds the metal wire from the spool to provide the metal wire to be advanced to form a loop of slack wire. Can be further included. The method may include repositioning the spool in one of the x, y, or z directions, or a combination thereof, to maintain the wire fed from the wire supply spool in the desired position. it can.

  The method can include rotating the roller in frictional contact with the metal wire to feed the metal wire into the housing. Rotation of the roller can be achieved by operating a motor attached to the roller, where the roller can be attached to the shaft of the motor or attached to the shaft attached to the motor. The motor is a stepping motor, a direct current (DC) motor, a brushless DC motor, a universal motor, a reluctance motor, a hysteresis motor, an induction motor, a synchronous motor, a split motor, a series motor, a composite motor, or any combination thereof. be able to. The slack wire loop, which can serve as a buffer between the wire tensioning unit and the wire tensioning unit, allows the advancement of the metal wire from the source to the plasma arc of the welding torch from the slack wire loop. It may be unaffected by the advancement of a certain amount of slack wire. The method can also include rotating a roller in frictional contact with the slack wire to deliver the slack wire to the welding torch. The rotation of the roller can be achieved by operating a motor attached to the roller, and the motor is a stepping motor or a direct current motor driven by an output control signal.

  There is provided herein a metal wire delivery system that can include a housing that receives a metal wire 180 from a wire supply spool of a wire supply unit, the housing having an opening 120 through which the metal wire 180 enters the housing. An ingress wire position detector 110 is provided. A wire tensioning unit comprising a wire feeder 200 receives a wire from a wire feed spool, and the wire feeder is a motorized grooved roller 220, a passive grooved roller 205, and a motor 225 attached to the grooved roller 220. And the wire is frictionally coupled to at least a portion of the grooves of each of the motorized grooved roller 220 and the passive grooved roller 205. The system also includes a wire buffer unit that includes a combination of three or more wire guides that form a loop of slack wire 185 from metal wire 180. The system also includes a slack wire delivery unit that includes a slack wire tensioning device 600 comprising a motorized grooved roller 620, a passive grooved roller 605, and a motor 625 attached to the grooved roller 620, where the slack wire 185 is Frictionally coupled to at least a portion of each groove of the motorized grooved roller 620 and the passive grooved roller 605, the slack wire tensioning device 600 removes the slack metal wire 185 from the loop of the slack wire 185 through the housing exit guide 1000 and out of the housing. Advance toward the plasma arc of the torch welding machine.

  In the wire buffer unit of the metal wire delivery system provided herein, the wire guide combination forming the slack wire loop is a double grooved roller 305 having a first groove and a second groove. A double grooved roller 320 having a roller attached to an arm 310 pivotally connected to a back plate 900 of the housing, and a first groove and a second groove, The first groove of the roller 320 and the first groove of the roller 320 form a channel to receive the metal wire 180 from the electric roller 220, and the first groove of the roller 305 is connected to the back plate 900. A first wire guide 300 including a double grooved roller 320 that is biased by a spring on an arm 310 connected to the metal wire 180 to engage. The combination of wire guides forming a loop of slack wire receives the metal wire 180 after the metal wire 180 has traversed the channel formed by the first groove of the roller 305 and the first groove of the roller 320. A second wire guide 400 positioned to the lower right of 300, comprising a grooved roller 405 attached to an arm 410 pivotally connected to the back plate 900 of the housing; A roller 420 with a roller 405 groove and a roller 420 groove forming a channel to receive the metal wire 180 from the wire guide 300, and the roller 405 groove connected to the back plate 900. A grooved roller 420 that is biased by a spring on an arm 410 connected to 430 to engage the metal wire 180. It is possible. This combination is a third wire guide 500 positioned at the lower left of the wire guide 300 and parallel to the wire guide 400, and the channel formed by the groove of the roller 405 and the groove of the roller 420 is connected to the metal wire 180. A wire guide 500 and a grooved roller 520 that includes a grooved roller 505 that receives a metal wire 180 after it has traversed and is attached to an arm 510 that is pivotally connected to a backplate 900 of the housing; The groove of the roller 505 and the groove of the roller 520 form a channel to receive the metal wire 180 from the wire guide 400, and the groove of the roller 505 is connected to the support 510 that is connected to the back plate 900. Including a grooved roller 520 biased by the upper spring to engage the metal wire 180. The metal wire 180 can form a loop of the slack wire 185 between the wire guide 400 and the wire guide 500, traverse the channel formed between the rollers 505 and 520, and the second groove of the roller 305. And advance through a channel formed between the second groove of the roller 320.

  In the metal wire delivery system provided herein, the grooves of the electric roller 220 and the passive roller 205 include protrusions for increasing the friction between the groove and the metal wire 180, either separately or in combination. The grooves of the electric roller 620 and the passive roller 605 can include protrusions to increase the friction between the groove and the metal wire 180, either separately or in combination. Any modification of the roller groove surface that increases the frictional force between the groove surface and the metal wire can be used as long as the wire surface is not damaged by the friction increasing technique. The motor 225 and the motor 625 are separately selected from a split motor, a series motor, a composite motor, an induction motor, a synchronous motor, a stepping motor, a DC motor, a brushless DC motor, a universal motor, a reluctance motor, and a hysteresis motor. Can do.

  The metal wire delivery system can include an entry wire position detector 110 that can include a sensor 122 that detects the position of the wire 180 within the opening 120. The sensor 122 repositions the wire supply spool in any one of the X, Y, or Z directions, or a combination thereof, to maintain the desired position of the metal wire 180 within the opening 120. It is possible to communicate with a control system that can control the position and orientation of the.

  In the metal wire delivery system provided herein, the metal wire 180 is wound around a wire supply spool and can be advanced into the housing by the action of the wire feeder 200. The metal wire 180 can contain aluminum, iron, cobalt, copper, nickel, carbon, titanium, tantalum, tungsten, niobium, gold, silver, palladium, platinum, zirconium, or alloys or combinations thereof. The metal wire 180 can contain titanium or a titanium alloy containing Ti in combination with one or a combination of Al, V, Sn, Zr, Mo, Nb, Cr, W, Si, and Mn. . The metal wire 180 is Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-6Al-2Sn-4Zr-6Mo, Ti-45Al-2Nb-2Cr, Ti-47Al-2Nb-2Cr, Ti-47Al-2W. Contains a titanium alloy selected from the group consisting of -0.5Si, Ti-47Al-2Nb-lMn-0.5W-0.5Mo-0.2Si, and Ti-48Al-2Nb-0.7Cr-0.3Si can do. The metal wire 180 can have a substantially circular cross section. The metal wire 180 can have a diameter in the range of about 0.5 mm to about 5 mm.

  The metal wire delivery system provided herein can include a pressure device 800 for modulating the amount of pressure exerted on the metal wire 180 by the grooved roller 205. The pressure device 800 includes a hydraulic, pneumatic, mechanical or electronically driven piston that increases the pressure applied to the grooved roller 205 when extended and reduces the pressure applied to the grooved roller 205 when contracted. Can be included.

  The metal wire delivery system provided herein can include a pressure device 850 for modulating the amount of pressure exerted on the metal wire 180 by the grooved roller 605. The pressurizing device 850 is a hydraulic, pneumatic, mechanical or electronically driven piston that increases the pressure applied to the grooved roller 605 when extended and reduces the pressure applied to the grooved roller 605 when contracted. Can be included.

  For the purpose of advancing the metal wire 180, the motor 225 of the wire feeder 200 may be connected to the roller 220 to rotate the roller 220 while the grooved roller 220 is in frictional contact with the metal wire 180. it can. To rotate the roller 620 while in frictional contact with the slack wire 185 for the purpose of pulling the slack metal wire 185 as a result of the rotation of the grooved roller 620, the motor 625 of the slack wire tensioning device 600 is turned on the grooved roller 620. Can be connected to. The motor 225 of the wire feeding device 200 can operate independently of the slack wire pulling device 600.

  In the metal wire delivery system provided herein, the combination of three or more wire guides causes the metal wire 180 to bend in a manner that does not cause permanent deformation of the metal wire 180 and the loose wire 185 to It is allowed to form a loop.

  A method of providing a metal wire to a plasma arc of a welding torch is also provided. The method includes the steps of providing a housing for receiving a metal wire, delivering a sufficient amount of metal wire from a wire source into the housing to form a loop of slack wire, and a certain amount of slack wire. Feeding the loose wire from the loop of the slack wire to the plasma arc of the welding torch and supplementing the slack wire fed to the plasma arc of the welding torch with an additional metal wire from the wire source to maintain the loop of the slack wire Providing a step. The amount of wire supplied from the wire source is generally sufficient to maintain a loop of slack wire to allow continuous delivery of the slack wire to the plasma arc of the welding torch. The loop of slack wire in the housing is maintained in place so that the metal wire can be continuously fed into the plasma arc of the welding torch to keep the metal wire in place in the plasma arc of the welding torch. . This ensures a stable and reliable wire feed rate and provides a stable mass input rate in the deposition process. The instability of the metal wire supply can cause unstable deposition and can lead to wire burnback and production outages. The slack wire loop is such that the delivery of the metal wire from the wire source into the housing is unaffected by a certain amount of slack wire tension from the slack wire loop to feed the plasma arc of the welding torch. Make it possible. The slack wire loop acts as a buffer between the tensioning unit that feeds the metal wire from the source into the housing and the slack wire tensioning unit that pulls the slack wire from the loop and feeds the slack wire to the plasma arc. Fulfills the function.

  The method can include rotating a roller in frictional contact with the metal wire to deliver the metal wire into the housing. Rotating the roller can be accomplished by operating a motor attached to the roller. The motor can be a split motor, a series motor, a composite motor, an induction motor, a synchronous motor, a stepping motor, a DC motor, a brushless DC motor, a universal motor, a reluctance motor, or a hysteresis motor. In some configurations, the motor is a stepping motor or a direct current motor driven by an output control signal. The method can include maintaining a predetermined amount of slack wire in the housing by delivering additional metal wire from the wire source into the housing to maintain a loop of slack wire. Delivery of the metal wire from the source into the housing may be unaffected by the delivery of an amount of slack wire from the slack wire loop to the plasma arc of the welding torch.

  The method can include rotating a roller in frictional contact with the metal wire to deliver the slack wire to the welding torch. The rotation of the roller can be achieved by operating a motor attached to the roller. The motor can be any motor, such as a stepping motor or a DC motor driven by an output control signal. The method provides a metal wire as a consumable electrode to a plasma arc of a welding torch. An exemplary welding torch is a plasma arc welding torch (PAW torch), such as a plasma transfer arc (PTA torch). PAW torches are used to heat and melt metal wires, such as gas metal arc welding (GMAW), particularly welding that uses non-reactive gases to form an arc (metal inert gas welding or MIG welding). It can have any configuration capable of generating an arc. The metal wire is used as a consumable electrode and is melted inside a plasma arc created by a welding torch using an electric arc, and the molten metal wire is deposited in a molten pool on the work piece to form a metal body. To form a near net shape metal body. The welding torch can also include a laser device, an electron beam gun, or a combination thereof.

  A method for producing a three-dimensional object of metallic material by three-dimensional free-form fabrication, wherein an object is produced by fusing successive deposits of metallic material onto a base material, wherein the metallic material is deposited Using the first heating device to preheat the base metal at the power position, and when preheating is performed, the molten metal material from the molten wire is on the base metal and the preheat zone or melt zone or portion of the base metal Providing the metal wire to a second heating device to heat and melt the metal wire so as to be deposited on the molten region; and a continuous deposit of molten metal material solidifies to form a three-dimensional object. A method is also provided that includes moving the base material in a predetermined pattern relative to the positions of the first heating device and the second heating device to form. The method includes a PAW torch, such as a PTA torch, as the first and second devices, or a PAW torch as the first heating device and a PAW torch as the second heating device, or a laser as the first heating device. And the second heating device as a laser device, the first heating device as a laser device and the second heating device as an electron beam gun, or the first heating device as an electron beam gun and a second heating device. A laser device can be used as the device, or a first electron beam gun can be used as the first heating device, and a second electron beam gun can be used as the second heating device. In a system that includes a PTA torch as a PAW torch, the PTA torch can be electrically connected to a DC power source such that the electrode of the PTA torch becomes the cathode and the metal wire becomes the anode. The method can utilize a coaxial powder delivery nozzle laser system as the first heating device and a laser system as the second heating device. The method can utilize a first electron beam device as the first heating device and a second electron beam device as the second heating device.

  Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

  It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed invention. I want.

  The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, explain the present invention. It plays a role in explaining the principle of the invention.

FIG. 1 is a diagram illustrating components of a metal wire delivery system provided herein. In the drawing, a wire supply unit 10, a wire tension unit 20, a wire buffer unit 30, and a slack wire delivery unit 40 are shown. These units interact to move the metal wires from the wire source to the plasma arc of the contact tip assembly welding torch. FIG. 2 is a schematic front view of an embodiment of a metal wire delivery system provided herein showing a loop of slack wire in a housing. The slack wire loop serves as a wire buffer that separates the wire feeding system that feeds the wire from the supply spool and the slack wire tensioning device that feeds the slack wire to the plasma arc or welding torch. FIG. 3 is a schematic front perspective view showing components of an exemplary wire supply unit. FIG. 4 is provided herein that illustrates the entry of the metal wire 180 into the housing through the wire receiving unit including the first receiving wheel 130 and the second receiving wheel 130 and the entry wire position detector 110. It is a general | schematic enlarged view of embodiment of the metal wire feeding system made. FIG. 5 illustrates a combination of a tensioning unit that includes a pressure device 800 that delivers wires from a wire source into a housing, a wire guide that forms and maintains a certain amount of slack wire in the housing, and a certain amount of slack. FIG. 6 is a schematic enlarged view of an embodiment of a metal wire system provided herein showing a slack wire tensioning unit including a pressurization device 850 that pulls the wire and delivers the slack wire to the plasma arc of the welding torch. FIG. 6 is a schematic enlarged view of an exemplary wire feeding device 200. FIG. 7 is a schematic enlarged view of an exemplary wire buffer unit 30 including a series of three wire guides 300, 400 and 500 that form a loop of slack wire. FIG. 8 is a schematic enlarged view of an exemplary slack wire tensioning device 600.

A. Definitions Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All patents, patent applications, published applications and publications, websites, and other published materials referenced throughout the disclosure herein are incorporated by reference in their entirety unless otherwise indicated. . In the event that there are a plurality of definitions for terms herein, those in this section prevail. When referring to URLs or other such identifiers or addresses, such identifiers may change and certain information on the Internet may appear or disappear, but searching the Internet It can be seen that equivalent information can be found. Their reference proves the availability and public dissemination of such information.

  As used herein, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

  As used herein, ranges and amounts can be expressed as “about” a particular value or range. “About” also includes the exact amount. Thus, “about 5 percent” also means “about 5 percent” and “5 percent”. “About” means within typical experimental error for the intended use or purpose.

  As used herein, “optional” or “optionally” means that the event or situation described subsequently occurs or does not occur, and that the event or situation occurs in the description Means that cases and events or situations do not occur.

  For example, an optional component in the system means that the component may or may not be present in the system.

  As used herein, “combination” refers to any relationship between two items or among three or more items. This relationship can be a spatial relationship or refers to the use of two or more items for a common purpose.

  As used herein, “plasma arc welding torch” or “PAW torch” refers to a welding torch that can be used in plasma arc welding. The torch is a gas heated to a high temperature to form a plasma that becomes conductive, then the plasma transfers the electric arc to the workpiece, and the intense heat of the arc melts the metal and / or two metals Designed so that the pieces can be fused together. The PAW torch can include a nozzle for constricting the arc, thereby increasing the power density of the arc. The plasma gas is typically argon. Plasma gas can be fed along the electrode and ionized and accelerated near the cathode. The arc can be directed toward the workpiece and is more stable than a free-burning arc (such as in a TIG torch). PAW torches also typically have an outer nozzle to provide shielding gas. The shielding gas can be argon, helium, or a combination thereof, and the shielding gas helps minimize the oxidation of the molten metal. In a PAW torch, the current can typically be up to 400A and the voltage can typically be about 25-35V (however it can be up to about 14 kW). The present invention is not bound by any particular choice or type of PAW torch. Any known or conceivable device that can function as a PAW torch can be used. An exemplary PAW torch is a plasma transfer arc (PTA) torch.

  As used herein interchangeably, the term “plasma transfer arc torch” or “PTA torch” refers to heating and exciting an inert gas flow to a plasma by an electric arc discharge, followed by an orifice (such as a nozzle). ) Refers to any device capable of transferring a flow of plasma gas, including an electric arc, through an orifice to form a constrained plume that transfers intense heat of the arc to a target area. The electrode and target area can be electrically connected to a DC power source such that the electrode of the PTA torch is the cathode and the target area is the anode. This ensures that the plasma plume containing the electric arc delivers a very concentrated heat flow to a small surface area of the target area with excellent control over the area and size of the heat flux supplied from the PTA torch. Become. Plasma transfer arcs have the advantage of providing a stable and consistent arc with little fluctuation and good resistance to length shifts between the cathode and anode. Therefore, the PTA torch is suitable for both forming a molten pool in the base material and heating and melting the metal wire supply material. The PTA torch may advantageously have an electrode made of tungsten and a nozzle made of copper. However, the present invention is not bound by any particular choice or type of PTA torch. Any known or conceivable device that can function as a PAW torch that provides a stable heat source for melting metal electrode wires can be used.

  As used herein, the term “power density” refers to the amount of power distributed over a unit area, eg, from a plasma arc, laser beam, or electron beam.

  As used herein, the term “metal material” refers to any known or conceivable metal or metal alloy that can be formed into a wire and used in a three-dimensional freeform fabrication process to form a three-dimensional object. . Examples of suitable materials include, but are not limited to, titanium and titanium alloys, i.e., Ti-6Al-4V alloys.

  As used herein, the term “similar metal material” means that the metal material consists of the same metal or metal alloy as the reference metal material.

  As used herein, the term “holding substrate” refers to an additional material that is the same as or different from the material of the holding substrate, using SFFF or solid freeform shaping techniques to form a workpiece. Refers to the target substrate on which is deposited. In the illustrated embodiment, the holding substrate is a flat sheet. In an alternative embodiment, the holding substrate may be a forged part. In an alternative embodiment, the holding substrate may be an object on which additional material is to be deposited. In an exemplary embodiment, the holding substrate can be part of the workpiece. The material of the holding substrate can be a metal or a metal alloy. In the illustrated embodiment, the holding substrate is made of the same metal as the wire feed material.

  The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, but are used herein. These elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first”, “second” and other numerical terms, as used herein, do not imply sequence or order, unless the context clearly indicates otherwise. . Accordingly, a first element, component, region, layer, or section described below is referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments. Can do.

  As used herein, the term “matrix” refers to a target material for receiving a molten metal material to form a three-dimensional object. The base material serves as a holding substrate when depositing the first layer of metal material. When one or more layers of metallic material are deposited on the holding substrate, the matrix becomes the top layer of deposited metallic material on which a new layer of metallic material is to be deposited.

  As used herein, a “slack wire” refers to a portion of a wire that is not held taut or held under tension.

  As used herein, “direct metal deposition” refers to a layered manufacturing process or 3D printing technique in which a workpiece is produced from a computer-aided design model.

  As used herein, a “friction enhancing surface” refers to a surface that has been modified to exert greater friction than an untreated smooth surface of the same material. Modification to a friction enhanced surface can include roughening the surface, including protrusions on the surface, or providing a roughened surface. The modified surface is in frictional contact between the modified surface and another surface, such as a metal wire that contacts the modified surface, to minimize slippage between the modified surface and the surface in contact with the modified surface. Can be enhanced (compared to an unmodified surface).

  As used herein, the term “workpiece” refers to a metal body that is produced using a three-dimensional freeform shaping method.

  The terms “computer-aided design model” or “CAD model” used interchangeably herein are any known object to be formed that can be used in the control system of an apparatus according to the second aspect of the invention. A virtual three-dimensional representation of or possible to adjust the position and movement of the holding substrate, and the physical object results in the construction of a physical object according to a virtual three-dimensional model of the object A virtual three-dimensional representation that can be used to operate a wire feeder's built-in welding torch as constructed by fusing a continuous deposit of metal material onto a holding substrate in a pattern. Point to. For example, a virtual vector of a three-dimensional object can be obtained by first dividing a virtual three-dimensional model into a set of virtual parallel horizontal layers and then dividing each of the parallel layers into a set of virtual quasi-one-dimensional pieces. It can be obtained by forming a structured layer model. The physical object is then controlled to deposit and fuse a series of quasi-one-dimensional pieces of metal material supply on the support substrate in a pattern that follows the first layer of the virtual vectorized stack model of the object. It can be formed by involving the system. Thereafter, by depositing and fusing a series of quasi-one-dimensional pieces of weldable material on the previously deposited layer in a pattern according to the second layer of the virtual vectorized stacking model of the object, Repeat the sequence for the two layers. For each successive layer of the object's virtual vectorized stack model, deposition continues on a layer-by-layer basis by repeating the deposition and fusing process until the entire object is formed. However, the present invention is not bound by any particular CAD model and / or computer software that implements the control system of the apparatus according to the present invention, and the present invention is not bound by any particular type of control system. The control system separates a first PAW torch for preheating the surface and / or forming a molten pool and a second PAW torch for melting the metal material feed wire into the molten pool. Any known or conceivable control system (such as CAD models, computer software, computer hardware, and actuators) that can construct a metal three-dimensional object by three-dimensional freeform shaping is used as long as it is adjusted to operate. Good.

B. Metal wire feeding system Buffering metal wire feeding system that maintains the amount of slack wire in the housing in place so that the metal wire can be continuously fed to the plasma arc of the welding torch of the contact tip assembly It has been found that it can be used as an additive to increase the deposition rate of molten metal on a shaped workpiece (manufactured using a direct metal deposition process (eg, additive manufacturing process)). A diagram of a typical metal wire delivery system is shown in FIG. The system includes a wire supply unit 10, a wire tension unit 20, a wire buffer unit 30, and a slack wire delivery unit 40. Although the units are schematically shown as being separated from each other, two or more or all of the units can be housed in a single structure, such as a chamber or housing.

  A more complete understanding of the present invention and its scope can be obtained from the accompanying drawings, the following detailed description of the presently preferred embodiments of the invention, and the appended claims, which are briefly summarized below. Can be obtained. A schematic view of a portion of an exemplary metal wire delivery system, not depicted of a wire supply unit, is shown in FIG.

  The components of an exemplary wire supply unit 10 are shown in FIG. The wire supply unit 10 includes components that allow a metal wire 180 to be provided to the wire tensioning unit 20. As shown in FIG. 3, the metal wire 180 can be provided from the metal wire supply spool 50 to the wire delivery system. Rotating about a fulcrum 55 on a vertical support element 60 movably connected to a transverse support element 65 movably connected to a first side support 70 and a second side support 71 The wire supply spool 50 can be attached to the cable. The fulcrum 55 enables the fulcrum 55 and the wire supply spool 50 to move in the vertical direction with respect to the Y axis (up and down with respect to the ground), and allows the supply spool 50 to be raised or lowered relative to the floor. Is movably connected to the vertical support element 60. This allows the metal wire 180 coming from the supply spool 50 to be maintained at the same height as the entry opening into the housing that houses the wire tensioning unit, wire buffering unit, and slack wire delivery unit. To.

  The vertical support element 60 may include a hydraulic, pneumatic, mechanical, or electrical lifting system for adjusting the vertical position of the fulcrum 55 to adjust the vertical position of the metal wire supply spool 50. Although an electric track system is depicted in FIG. 3, any lifting system can be used. The change in the vertical positioning of the metal wire supply spool 50 allows the metal wire 180 unwound from the supply spool 50 to be maintained at substantially the same height as when the wire is removed from the spool. Thus, the diameter of the wire wound around the supply spool 50 when the wire is drawn out from the spool is dealt with.

  The vertical support element 60 is movably connected to the transverse support element 65 to allow the vertical support element 60 to move horizontally (left and right as viewed from the viewpoint shown in FIG. 3) relative to the X axis. . This allows the wire supply spool 50 to be repositioned closer or further away from the wire feed system housing. The transverse support element 65 can include a hydraulic, pneumatic, mechanical, or electrical system for adjusting the position of the vertical support element 60 to adjust the horizontal position of the metal wire supply spool 50. Although a motorized track system is depicted in FIG. 3, any position changing system can be used to adjust the position of the vertical support element 60.

  The transverse support element 65 is movably attached to the side support elements 70, 71 so that the transverse support element 65 moves back and forth (approaching and separating from the viewpoint shown in FIG. 3) relative to the Z axis. It becomes possible. This is unwinding from the metal wire supply spool 50 in order to maintain the metal wire 180 approximately in the center of the opening 120 of the sensing device 110 (shown in detail in FIG. 7) as the wire is unwound from the supply spool 50. Allows metal wire 180 to be repositioned. Each of the side support elements 70 and 71 can include a hydraulic, pneumatic, mechanical, or electrical system for adjusting the position of the transverse support element 65 to adjust the position of the metal wire supply spool 50. Although a motorized track system is depicted in FIG. 3, any position changing system can be used to adjust the position of the transverse support element 65.

  The side support body 70 can be attached to the front mounting support body 72 and the rear mounting support body 74 that can be detachably fixed to the ground via bolts and nuts by means of mounting plates. The side support 71 can be attached to the front attachment support 73 and the rear attachment support 75 that can be removably fixed to the ground via bolts and nuts by means of attachment plates. The front mounting supports 72 and 73 or the rear mounting supports 74 and 75 can be attached to each other using cross beams. FIG. 2 depicts the rear mounting supports 74, 75 attached to each other using cross beams 78.

  A control system (not shown) detects the wire feed system sensing device 110 (FIG. 2) to maintain the desired positioning of the metal wire 180 as the metal wire 180 enters the housing through the entry opening 120. 4 and and partially shown in FIG. 5), the metal wire supply spool can be repositioned in the X, Y, or Z direction. The control system includes a computer processor or central processing unit (CPU), a CPU display, one or more power supplies, a power supply connection, a signal module as input and / or output, an integrated shield of analog signals, a storage device, a circuit board , A memory chip or other storage medium, a non-transitory computer readable storage medium having a computer readable program embodied therein, or any combination thereof. The computer readable program may include suitable software for partially or fully automating any one or combination of systems. The computer readable program may include appropriate software for monitoring and / or adjusting the parameters. Exemplary parameters include the state of one or more sensors, the tension of the metal wire, the speed at which the metal wire passes through the target location, the amount of metal wire remaining on the wire supply spool, or any combination thereof. . Exemplary control systems include, but are not limited to, Siemens AG (Munich, Germany), SIMATIC-S7-1500, Bosch Rexroth AG (IntraMotion MTX system, available from Lohr am Main, Germany), and SIGMATEK. & Co. SIGMATEK C-IPC (compact industrial computer system) available from KG (Lamprechthausen, Austria).

  The control system includes a wire delivery device 200, a wire buffer unit including a series of three wire guides 300, 400 and 500, used to form a loop of the slack wire 185, and a slack wire 185 pulling chamber. To maintain the metal wire 180 approximately in the center of the opening 120 of the housing that houses the slack wire tensioning device 600 that feeds the slack wire 185 out of the housing through the exit guide 1000 (see FIG. 2). Including a computer capable of executing a program capable of directing operation of a mechanism to reposition any one or combination of 55 vertical positions, vertical support element 60 positions, and transverse support element 65 positions in the required direction. it can.

  Metal wire feeding that keeps the amount of slack wire in the housing in place so that the metal wire can be continuously fed into the plasma arc of the welding torch and maintained in place in the plasma arc of the welding torch It has been found that the system can be used to increase the rate of molten metal deposition on a shaped workpiece. The slack wire loop serves as a buffer to maintain a stable and reliable wire feed rate, ensuring a stable mass input rate for the production process. Instability not only causes unstable deposition, but can also cause wire burnback and production interruptions. The slack wire loop can minimize wire speed, tension or positional instability. The wire feed rate can be maintained substantially constant so that the metal wire is continuously fed to the plasma arc of the welding torch for melting on the workpiece. Continuous feeding of metal wire to the welding torch prevents non-smooth or discontinuous deposition of metal on the workpiece. Any unintended discontinuities in the deposition can result in imperfections, irregularities, and defects in the workpiece, which can ultimately lead to delamination, fatigue, or cracks in the final product. Make it unusable for potentially intended purposes. Increasing the rate of continuous feeding of the metal wire also allows the rate of molten metal deposition on the workpiece to be increased, increasing the efficiency of the freeform fabrication process.

  Referring to FIG. 1, the wire tensioning unit 20 can be controlled independently of the slack wire delivery unit 40. Thus, the metal wire can be at a rate that is different from or substantially the same as the rate at which the slack wire is provided to the plasma arc of the welding torch outside the wire feed housing by the action of the slack wire delivery unit 40. At a speed, it can be fed from the wire supply unit 10 into the housing by the action of the wire tensioning unit 20. In this arrangement, the amount of wire delivered into the housing by the action of the wire tensioning unit 20 is unaffected by the amount of slack wire pulled by the slack wire delivery unit to feed the plasma arc of the welding torch. Can be.

  In general, the metal wire can be provided on a supply spool around which the metal wire is wound. In order to provide the metal wire to the housing, it is necessary to rotate the entire large number of wires wound around the supply spool. The mass and inertial effects of removing the wire from the wire supply spool by the tensioning unit can be isolated from the wire provided to the welding torch by the loop of slack wire in the housing. The effect of mass and inertia that removes the wire from the wire source spool is isolated from the wire being delivered to the welding torch, thus minimizing wire slippage within the housing. In addition, any influence of inertia from the wire supply spool that could result in the wire being pulled back to the wire supply spool is eliminated by the slack wire loop, thereby allowing the metal wire to be welded to the plasma arc of the welding torch. A continuous feed is possible, minimizing undesirable discontinuous deposition of molten metal on the workpiece. Since the continuous supply of metal wire is performed on the plasma arc of the welding torch, the deposition process can be maintained smoothly and continuously.

  Metal wires can be fed from the wire supply unit 10 into the housing using the wire tensioning unit 20. As shown in FIGS. 2, 4, and 5, the wire delivery system can include a sensing device 110 that includes an opening 120 through which a metal wire 180 from the wire supply spool 50 can be fed into the housing. The metal wire 180 can be maintained approximately at the center of the opening 120 by the tension exerted by the wire feeder 200. As depicted in FIG. 4, the metal wire 180 can enter the housing through the opening 120 of the sensing device 110 and travels through a wire receiving unit that includes a passive receiving wheel 130 and a passive receiving wheel 135. The passive receiving wheel 130 and the passive receiving wheel 135 together form a channel between the passive receiving wheel 130 and the passive receiving wheel 135 through which the metal wire 180 can pass. Optionally, the receiving wheel 130 or the receiving wheel 135 can be biased by a spring to engage the metal wire 180. Referring to FIG. 5, the metal wire 180 can be advanced through optional brackets 140 and 145 by the tensile force exerted on the metal wire 180 between the passive grooved roller 205 and the motorized grooved roller 220. Brackets 140 and 145 can be used as mounts for other devices. For example, a camera for observing the metal wire 180 when the metal wire 180 enters the housing can be attached to the bracket 140. A brush can be attached to the bracket 145 to remove any loose material or debris. In some configurations, brackets 140 and 145 are excluded.

  Referring to FIG. 2, the housing can include a backplate 900 that defines a back portion of the housing. A frame 100 is attached to the back plate 900, and a side wall that defines a lateral outer edge of the housing is attached to the frame 100 (not shown). The ceiling and floor can optionally be connected to side walls (not shown) and, if present, can define the top and bottom of the housing, respectively. The upper transparent window 103 can be connected to the frame 100 via a hinge (not shown), and the two lower transparent doors 104 are connected to the frame 100 via the hinge 101. The transparent window 103 and the two lower transparent doors 104 constitute the front part of the housing. The windows and doors can be made of any material such as glass, acrylic (polymethyl methacrylate or PMMA), glycol modified polyethylene terephthalate (PETG), or polycarbonate. Transparent windows and transparent doors allow visualization of the metal wire delivery system without having to open the housing window or door. The sensor 122 can be positioned around the opening 120 to determine the position of the metal wire 180 as the metal wire 180 moves from the opening 120 into the housing. The sensor 122 repositions the metal wire supply spool in the X, Y, and / or Z direction to maintain the desired positioning of the metal wire 180 as the metal wire 180 enters the housing through the opening 120. Information can be sent to a control system (not shown) that can be deployed. Exemplary sensors include optical sensors, optical fiber sensors, proximity sensors, photoelectric sensors, magnetic sensors, and combinations thereof. These sensors are commercially available (see, eg, Industrial Automation-Omron Corporation, Kyoto, Japan). In some configurations, an array of fiber optic sensors can be positioned around the aperture 120.

  Still referring to FIG. 2, the housing exit guide 1000 can guide the metal wire 180 out of the housing and into the wire guide of the plasma arc welding torch. The case exit guide 1000 is a case that is on a straight line with the detection device 110 and parallel to the detection device 110 so that a straight line is obtained when the opening 120 of the detection device 110 and the case exit guide 1000 are connected. Can be positioned directly on the sidewalls of The housing protects the wire from accidental contact with bare hands and prevents touching the metal wire 180 with bare hands. It is desirable to minimize contamination as this housing can minimize wire contamination and wire contamination can cause imperfections in the deposited workpiece. The housing may include one or more sensors that monitor the status of the window 102 and / or the door 104. The control system can be programmed to stop the deposition process whenever one of the window 102 and / or door 104 is open. Exemplary sensors include electrical contact sensors, optical sensors, proximity sensors, photoelectric sensors, magnetic sensors, and combinations thereof. For example, cylindrical proximity sensors (Industrial Automation-Omron Corporation, Kyoto, Japan) can be used in windows or doors or both.

  An exemplary wire tensioning unit includes a wire feeder that can include an electric roller in frictional contact with a wire fed from a wire feed spool. The motor can feed the metal wire into the housing by rotating the roller. Any type of motor can be used. Exemplary motors include a split motor, a series motor, a composite motor, an induction motor, a synchronous motor, a stepping motor, a DC motor, a brushless DC motor, a universal motor, a reluctance motor, and a hysteresis motor. The motor that drives the wire supply roller can be a conventional DC motor driven by an output control signal. The output control signal may have a repetitive duty cycle characteristic that defines an on time while power is being supplied and an off time when power is not being supplied. The motor can be attached directly to the roller, or the roller can be attached to the shaft of the motor or attached to the shaft attached to the motor. A reduction gear head can be used to connect the motor to the roller. Using an output control signal with duty cycle characteristics to run the motor allows for precise control of wire advancement with the ability to control and avoid the effects of rotational inertia or unwinding. As a result, an excess amount of additional wire is not fed into the housing, but only an amount sufficient to maintain the desired amount of slack wire is brought into the housing. A motor for driving the wire supply roller includes a stepping motor that allows an accurate amount of wire to be advanced from the wire supply spool into the housing by electronically controlling the number of output pulses supplied to the drive motor. can do.

  An exemplary wire feeder 200 is depicted in FIG. The metal wire 180 from the supply spool 50 (shown in FIG. 3) is fed into the housing by the action of the wire feeding device 200 including the motorized grooved roller 220 and the passive grooved roller 205 attached to the motor 225. The The motor 225 can be any motor, such as a conventional direct current (DC) motor driven by an output control signal, or by electronically controlling the number of electrical command pulses supplied to the drive motor. It can be a stepper motor that allows a precise amount of wire to be advanced from the wire supply spool into the housing. The metal wire 180 is guided to a position between the groove of the motorized grooved roller 220 attached to the motor 225 and the groove of the passive grooved roller 205. The grooved roller 205 and the grooved roller 220 include a protrusion that can engage with the metal wire 180 in the groove, and can pull the metal wire 180 through the groove between the rollers. The protrusions in the groove can increase the frictional force between the roller groove and the metal wire 180, allowing the roller to frictionally engage the metal wire 180 and advance the metal wire 180 through the roller. .

  Passive grooved roller 205 and motorized grooved roller 220 are typically made of steel, but are Inconel® nickel-chrome alloy, Monel® nickel-copper alloy, or ToughMet®. ) It can be made of other alloys such as copper-nickel-tin alloy. If the roller is made of or contains steel, the steel can be carbon steel or stainless steel. Exemplary steels include S355, S355JR, S355J2, S355J2 + N, and S450J0. Grooved rollers are commercially available (e.g., in Products for Industry, Inc., Brighton, CO, USA, and SBI International, Holland, Austria).

  The amount of pressure in the orthogonal direction that the passive grooved roller 205 exerts on the metal wire 180 can be adjusted by the selection of the groove configuration in the grooved roller 205 and the pressure exerted by the pressure device 800. The roller can have a V-shaped groove, a U-shaped groove, a tapered groove, a cylindrical groove, a 60 ° groove, a 90 ° groove, or a pulley groove. By increasing the pressure exerted by the pressure device 800, the pinching pressure exerted on the wire by the grooved roller 205 is increased. If the pressure exerted by the pressure device 800 is too small, the metal wire 180 may slip from between the grooved roller 205 and the grooved roller 220. If the pressure exerted by the pressurizing apparatus 800 is excessive, the metal wire 180 may be deformed. A pressure of up to 3 bar can be applied by the pressurizing device 800. The pressure device 800 includes a hydraulic, pneumatic, mechanical or electronically driven piston that increases the pressure applied to the grooved roller 205 when extended and reduces the pressure applied to the grooved roller 205 when contracted. Can be included. Due to the action of the motor 225, tension is generated in the metal wire 180 between the electric grooved roller 220 and the wire supply spool 50. The metal wire 180 can be maintained at the approximate center of the opening 120 by this tension.

  After passing through the path created between the passive grooved roller 205 and the motorized grooved roller 220, the metal wire 180 is a wire that includes the passive grooved roller to form a loop of the slack wire 185 in the housing. Proceed to the wire buffer unit 30, which includes the combination of guides. An exemplary configuration of a wire guide for the wire buffer unit 30 is depicted in FIG. In the configuration depicted in FIG. 7, a series of three passive wire guides 300, 400 and 500 are used to form a loop of slack wire. The grooved rollers of the wire guides 300, 400 and 500 are smooth and are typically made of steel. The steel can be carbon steel or stainless steel. Exemplary steels include S355, S355JR, S355J2, S355J2 + N, and S450J0. After leaving the motorized grooved roller 220, the metal wire 180 enters the first groove of the double grooved wire guide 300 that includes the double grooved roller 305 and the double grooved roller 320. The roller 305 can be attached to an arm 310 that can be pivotally connected to the back plate 900 so that the arm 310 can passively rotate about the connection axis in a plane parallel to the back plate 900. The roller 305 can be biased by a spring connected to the support 330 to engage with the metal wire 180.

  The metal wire 180 is guided through a channel formed between the rollers 305 and 320 of the wire guide 300 and proceeds toward the wire guide 400 positioned at the lower right of the double groove roller 320 of the wire guide 300. The wire guide 400 can include a grooved roller 405 and a grooved roller 420. The roller 405 can be attached to the arm 410 that can be pivotally connected to the back plate 900 so that the arm 410 can passively rotate about the connection axis in a plane parallel to the back plate 900. The roller 405 can be engaged with the metal wire 180 by being biased by a spring connected to the support 430.

  The metal wire 180 is guided through a channel formed between the rollers 405 and 420 of the wire guide 400 and is positioned at the lower left of the double groove roller 320 as depicted in FIG. As it travels toward the guide 500, it forms a loop of slack wire. The wire guide 500 includes a grooved roller 505 and a grooved roller 520. The roller 505 can be attached to the arm 510 that can be pivotally connected to the backplate 900 such that the arm 510 can passively rotate about the connection axis in a plane parallel to the backplate 900. Roller 505 can be biased by a spring connected to support 530 to engage metal wire 180. Metal wire 180 between wire guides 400 and 500 forms a single loop of slack wire 185. The loop of the slack wire 185 can have an oval shape due to the effect of gravity on the unsupported metal wire between the wire guides 400 and 500.

  The more slack wires that can enter the housing, the larger the single loop of slack wire 185. The loop of slack wire 185 serves as a buffer to ensure that sufficient metal wire 180 is present in the correct orientation to meet the requirements of the deposition process. When the deposition process is performed at a higher rate, more metal wire 180 can be placed in the housing, and the loop of slack wire 185 is relatively large so that the loop can occupy most of the housing. Can be. When the deposition process is performed at a slower rate, less slack wire is required, so fewer metal wires 180 can be placed in the housing, and the loop of slack wire 185 is the loop of the housing. It can be small to occupy a smaller part.

  The metal wire delivery system provided herein can include a loop sensing device 700 that can detect the presence of a slack wire loop in the housing. An exemplary loop sensing device can include multiple sensors, as shown in FIG. As depicted in FIG. 2, the loop sensing device 700 includes sensors 710, 720, 730, and 740 that can be used to determine the amount of slack wire in the housing. The sensor can communicate with a control system that is responsive to feedback received from the sensor. Each sensor can separately send a signal to the control system when the metal wire 180 is detected by the sensor. In response to the signal from the sensor, the control system modulates the supply of additional wire drawn into the housing from the wire source, thereby reducing the size of the slack wire loop and thus the amount of slack wire in the housing. Can be adjusted. Exemplary sensors include optical sensors, optical fiber sensors, proximity sensors, photoelectric sensors, magnetic sensors, and combinations thereof. These sensors are commercially available (see, eg, Industrial Automation-Omron Corporation, Kyoto, Japan). In some configurations, sensors 710, 720, 730, and 740 are fiber optic sensors or proximity sensors that do not require contact with a slack wire.

  For example, in the exemplary embodiment shown in FIG. 2, as additional metal wire 180 is carried into the housing by the action of wire feeder 200, the bottom of the loop of slack wire 185 begins to drop. Due to the positioning of the wire guides 300, 400 and 500 and the effect of gravity on the unsupported slack wire, the loop of slack wire 185 has a generally oval shape. Sensor 720 sends a signal to the control system when the bottom of the loop of slack wire 185 is in proximity to sensor 720. The control system is preprogrammed to deliver more wires into the housing in response to the signal from sensor 720. As more metal wire 180 is fed into the housing, the lower portion of the slack wire loop is lowered. Sensor 730 sends a signal to the control system when the bottom of the loop of slack wire 185 is proximate to sensor 730. The control system is preprogrammed to deliver fewer wires into the housing in response to a signal from sensor 730. The interaction between the bottom of the loop of the slack wire 185 and the sensors 720 and 730 can provide a substantially constant supply of slack wire in the housing for feeding the plasma arc of the welding torch during the deposition process.

  If the deposition process slows down significantly, the bottom of the loop of slack wire 185 is lowered toward the floor of the housing, close to sensor 740 and detected by sensor 740. The control system receives a signal from the sensor 740 in order to prevent excess slack wires from gathering in the housing, which can entangle with the wire itself or otherwise prevent the wire from passing easily through the system. The control system can be programmed to stop the motor 225 to prevent additional metal wires 180 from entering the enclosure.

  If the deposition process is greatly accelerated, or if the supply of wire supply cannot keep up with the demand for metal wire 180, the bottom of the loop of slack wire 185 rises toward the top of the housing, first sensor 720. Proximity to. If enough metal wire is not brought into the housing in response to a signal from sensor 720 to the control system, the bottom of the loop of slack wire 185 continues to rise upward. The loop eventually approaches the sensor 710 and is detected by the sensor 710. Sensor 710 can be programmed to shut down the entire system, including motors 225 and 625 and a plasma arc welding torch, and the control system receives signals from sensor 710. When the deposition process is interrupted. The outage minimizes the risk of equipment damage.

  After the slack wire 185 has moved away from the roller of the wire guide 500, the slack wire 185 is between the second groove of the double grooved roller 305 of the wire guide 300 and the second groove of the double grooved roller 320. Proceed toward a slack wire tensioner 600 that includes a motor 625 and a passive grooved roller 605 guided through the channel and connected to a motorized grooved roller 620.

  The motor 625 electronically controls the number of input electrical pulses supplied to a conventional direct current (DC) motor driven by the output control signal or to the drive motor so that an accurate amount of wire can be accommodated from the wire supply spool. It can be any motor, such as a stepping motor that allows it to be advanced into the body. The slack wire 185 is guided to a position between the motorized grooved roller 620 attached to the motor 625 and the passive grooved roller 605. The passive grooved roller 605 or the motorized grooved roller 620 or both can include protrusions in the groove that can engage the slack wire 185 and advance the slack wire 185 through the roller. The protrusions in the groove can increase the frictional force between the roller groove and the slack wire 185, allowing the roller to frictionally engage the slack wire 185 and pull the slack wire 185 through the roller.

  Passive grooved roller 605 and motorized grooved roller 620 are typically made of steel, but are Inconel® nickel-chromium alloy, Monel® nickel-copper alloy, or TouchMet®. ) It can be made of other alloys such as copper-nickel-tin alloy. If the roller is made of or contains steel, the steel can be carbon steel or stainless steel. Exemplary steels include S355, S355JR, S355J2, S355J2 + N, and S450J0. Grooved rollers are commercially available (e.g., in Products for Industry, Inc., Brighton, CO, USA, and SBI International, Holland, Austria).

  The amount of pressure in the orthogonal direction that the passive grooved roller 605 exerts on the slack wire 185 can be adjusted by the selection of the groove configuration in the grooved roller 605 and the pressure exerted by the pressure device 850. The roller can have a V-shaped groove, a U-shaped groove, a tapered groove, a cylindrical groove, a 60 ° groove, a 90 ° groove, or a pulley groove. By increasing the pressure exerted by the pressure device 850, the pinching pressure exerted on the wire by the grooved roller 605 increases. If the pressure exerted by the pressure device 850 is too small, the slack wire 185 may slip from between the grooved roller 605 and the motorized grooved roller 620. If the pressure exerted by the pressurizing device 850 is excessive, the metal wire 180 may be deformed. A pressure of up to 3 bar can be applied by the pressurizing device 800.

  The pressure device 850 is a hydraulic, pneumatic, mechanical or electronically driven type that increases the pressure applied to the passive grooved roller 605 when extended and reduces the pressure applied to the passive grooved roller 605 when contracted. A piston can be included. The wire is pulled by the action of the motor 625, and as a result, the loop of the slack wire 185 shrinks. The motors 225 and 625 can be operated separately, and the individual action of these motors allows adjustment of the amount of slack wire in the housing and the size of the slack wire 185 loop. After passing through the grooved roller 605 and the motorized grooved roller 620, the slack wire 185 advances through the housing exit guide 1000 and is delivered to the wire guide of the plasma arc welding torch device.

  The motor 625 can communicate with a welding device that can send a signal to the motor 625 to advance the slack wire 185 out of the housing through the housing exit guide 1000 and supply the slack wire 185 to the welding torch device. .

  The loop of the slack wire 185 allows the pulling action of the wire demanding slack wire pulling unit to be separated from the possible adverse effects caused by the supply spool 50 providing the metal wire 180. The rotational inertia from the spool and the mass of the wire drawn from the wire spool can be addressed by the introductory portion of the wire delivery system (such as the sensing device 110 and the tensioning unit motor 225) or absorbed by the loop of the slack wire 185. And prevent rotational inertia or mass from being transmitted to the wire in the vicinity of the welding torch. The system allows the unwinding of the wire on the inlet side of the wire delivery system to be separated from the advance of the wire to the welding torch. Since the loop of slack wire hangs freely from the wire guides 400 and 500 within the housing, the wire of the loop can be easily advanced by the action of the motor 225 or 625 without being subjected to tension. The loop of slack wire 185 also allows the wire supply spool 50 to be replaced without stopping the metal deposition on the workpiece. The loop of slack wire 185 also provides a length of wire as a buffer between the wire supply spool 50 and the wire feeder of the welding torch so that the wire is provided to the welding torch at a constant rate. to enable.

  The wire delivery system is designed to reduce wire slip that may occur due to the rotational inertia of the wire supply spool. Slip can cause wire deformation or other problems that manifest when attempting to align the metal wire into the arc of the welding torch. In preferred embodiments, the wire is straight rather than curved as used in some systems. In particular, the metal wire is straight and can be used in a two torch system, as described in Tempfer (US 2014/0061165). In such systems, it is important that the wire feeding unit be able to deliver straight metal wires in order to maintain the alignment of the metal wires in the plasma arc of the welding torch.

  Each of the components of the wire feeding system in the housing excluding the detection device 110 is finally connected to the back plate 900. The backplate 900 can comprise any material suitable for supporting the components of the wire delivery system. In some embodiments, the backplate 900 is made of steel selected from carbon steel, stainless steel, S355, S355JR, S355J2, S355J2 + N, and S450J0, AA6063, AA6063-T6, EN AW-6063T6, AW-6082-T6. , And aluminum alloys selected from EN AW-6063T6 / 6082T6, Inconel (R) nickel-chromium alloy, Monel (R) nickel-copper alloy, or ToughMet (R) copper-nickel- It can be a tin alloy.

  The metal wire 180 forming the loop of the slack wire 185 can comprise any metal used in plasma arc welding, particularly plasma transfer arc welding. The metal wire can be titanium or can contain titanium. The metal wire is, or contains, a titanium alloy containing Ti in combination with one or a combination of Al, V, Sn, Zr, Mo, Nb, Cr, W, Si, and Mn. be able to. For example, exemplary titanium alloys include Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-6Al-2Sn-4Zr-6Mo, Ti-45Al-2Nb-2Cr, Ti-47Al-2Nb-2Cr, Ti -47Al-2W-0.5Si, Ti-47Al-2Nb-lMn-0.5W-0.5Mo-0.2Si, and Ti-48Al-2Nb-0.7Cr-0.3Si. The metal wire can contain aluminum, iron, cobalt, copper, nickel, carbon, titanium, tantalum, tungsten, niobium, gold, silver, palladium, platinum, zirconium, alloys thereof, and combinations thereof. The metal wire can have a circular cross section. The metal wire can have any diameter or size. In some embodiments, the diameter of the metal wire can range from about 0.1 mm to about 10 mm. For example, the metal wire can have a diameter of, for example, 1.0 mm, 1.6 mm, or 2.4 mm.

  The wire supply system can be used to supply metal wire to any welding torch. An exemplary welding torch is a PAW torch. PAW torches are electric arcs for heating and melting metal wires, such as gas metal arc welding (GMAW), particularly welding that uses an inert gas to form an arc (metal inert gas welding or MIG welding). Can have any configuration capable of generating An exemplary PAW torch is a PTA torch. The metal wire is melted in the plasma generated by the torch using an electric arc, and the molten metal wire is deposited in a molten pool on the workpiece and added to the metal body to form a near net shape metal. Form the body. The feed rate and positioning of the metal wire ensures that the metal wire is continuously heated and melted when the metal wire reaches the intended position above the molten pool of the base metal. Furthermore, it can be controlled and adjusted according to the efficiency of power supply to the PAW torch. Exemplary welding systems are described in Guldberg (WO 2011/019287), Ireland et al. (US Pat. No. 7,220,935), Comon et al. (US Pat. No. 9,145,832), Cooper et al. (U.S. Patent Application Publication No. 2010/0276396), Biskup et al. (U.S. Patent Application Publication No. 2013/0140280), and Tempfer (U.S. Patent Application Publication No. 2014/0061165).

  While the foregoing description describes new details in considerable detail, this description is not to be construed as limiting the scope of the invention, but rather as providing an illustration of various embodiments of the invention. Should.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

The following is a list of reference numbers used in the specification and attached drawings.
DESCRIPTION OF SYMBOLS 10 Wire supply unit 20 Wire tension | tensile_strength unit 30 Wire buffer unit 40 Loose wire delivery source 50 Wire supply spool 55 Support point 60 Vertical support element 65 Transverse support element 70 1st side support element 71 2nd side support element 72 Front part Mounting support 73 Front mounting support 74 Rear mounting support 75 Rear mounting support 78 Frame cross beam 100 Frame 101 Hinge 103 Upper transparent window 104 Lower transparent door 110 Detector 120 Opening 122 Position sensor 130 First wire receiving unit Receiving wheel 135 Second receiving wheel of the wire receiving unit 140 Optional bracket 145 Optional bracket 180 Metal wire 185 Slack wire 200 Wire feeder 205 Passive grooved roller 210 Arm 220 Motorized grooved low 225 motor 300 first slack wire guide 305 double grooved roller 310 arm 320 double grooved roller 330 support 400 second slack wire guide 405 passive grooved roller 410 arm 420 passive grooved roller 430 support 500 first Three slack wire guides 505 Passive grooved roller 510 Arm 520 Passive grooved roller 530 Support 600 Loose wire pulling device 605 Passive grooved roller 610 Arm 620 Motorized grooved roller 625 Motor 700 Loop detection device 710 Sensor 720 Sensor 730 Sensor 740 Sensor 780 Support element 790 Support element 800 Pressurization device 850 Pressurization device 900 Back plate 1000 Housing exit guide

Claims (28)

An adjustable wire supply spool;
A housing with an entry wire position detector including an opening;
A first motorized grooved roller; a first passive grooved roller; and a first motor attached to the first motorized grooved roller, the first motorized grooved roller and the first A passive grooved roller forming a channel between the first motorized grooved roller and the first passive grooved roller;
A combination of at least three slack wire guides, wherein a first slack wire guide is positioned rearwardly and linearly with the wire feed device, and a second slack wire guide is the first slack wire guide; A combination of at least three slack wire guides positioned at the lower right of one slack wire guide and a third slack wire guide positioned at the lower left of the first slack wire guide;
A second motorized grooved roller; a second motorized grooved roller; and a second motor attached to the second motorized grooved roller; and the second motorized grooved roller and the second motorized grooved roller. A slack wire pulling device, wherein the passive grooved roller forms a channel between the second motorized grooved roller and the second passive grooved roller;
A metal wire feeding system comprising a housing exit guide. The first slack wire guide is
A first double grooved roller having a first groove and a second groove, wherein the first double groove is attached to a first arm pivotally connected to the back plate of the housing. Grooved rollers,
A second double grooved roller having a first groove and a second groove, wherein the first groove of the first grooved roller and the first grooved roller A groove forms a channel between the first groove of the first grooved roller and the first groove of the second grooved roller, and the first double grooved roller A second double grooved roller in which the first groove is biased by a spring on the first arm connected to a first support connected to the back plate of the housing And
The second slack wire guide is
A third passive grooved roller attached to a second arm pivotally connected to the back plate of the housing;
A fourth passive grooved roller, wherein the groove of the third passive roller and the groove of the fourth passive roller are the groove of the third passive roller and the groove of the fourth passive roller. And a groove on the third passive roller by a spring on the second arm connected to a second support connected to the back plate of the housing. A fourth passive grooved roller that is biased, and the third slack wire guide,
A fifth passive grooved roller attached to a third arm pivotally connected to the back plate of the housing;
A sixth passive grooved roller, wherein the groove of the fifth passive roller and the groove of the sixth passive roller are the groove of the fifth passive roller and the groove of the sixth passive roller. And a groove on the fifth passive roller by a spring on the third arm connected to a third support connected to the back plate of the housing. An energized sixth passive grooved roller;
The first slack wire guide, the second slack wire guide, and the third slack wire guide from the first wire guide to the second wire guide, the third wire guide, and the The metal wire feeding system according to claim 1, wherein a loop path returning to the first wire guide is formed.   The groove of any one of or a combination of the first motorized grooved roller, the first passive grooved roller, the second motorized grooved roller, and the second passive grooved roller The metal wire feeding device according to claim 1, wherein the friction of the surface of the metal wire is enhanced. The metal wire feed according to any one of claims 1 to 3, wherein the first motor and the second motor are each selected from a DC motor and a stepping motor driven by an output control signal. Supply system.   The metal wire feeding system according to any one of claims 1 to 4, wherein the entry wire position detector further includes a first sensor that detects a position of the metal wire in the opening.   6. The metal wire feed of claim 5, wherein the first sensor communicates with a control system that can reposition the wire supply spool in at least one of the X, Y, or Z directions, or any combination thereof. Supply system.   8. The metal wire feed of claim 7, wherein the housing further comprises a transparent window or a transparent door or both to allow viewing of components within the housing without opening the housing. system.   The metal wire delivery system according to claim 7, wherein the transparent window or transparent door is made of glass, acrylic (poly (methyl methacrylate) or PMMA), glycol modified polyethylene terephthalate (PETG), or polycarbonate.   The metal wire feeding system according to any one of claims 1 to 8, wherein the wire feeding device is configured to feed the wire wound around the wire supply spool into the housing.   The metal wire feeding system according to any one of claims 1 to 9, further comprising a first pressure device for adjusting an amount of pressure exerted by the first passive grooved roller.   When the first pressure device increases the pressure applied to the first passive grooved roller when moved in the first direction and moves in the second direction, the first passive groove 11. The metal wire delivery system of claim 10, comprising a hydraulic, pneumatic, mechanical or electronically driven piston that reduces the pressure applied to the roller.   The metal wire feeding system according to any one of claims 1 to 11, further comprising a second pressurizing device for adjusting an amount of pressure exerted by the second passive grooved roller.   When the second pressure device increases the pressure applied to the second passive grooved roller when moved in the first direction and moves in the second direction, the second passive groove 13. The metal wire delivery system of claim 12, comprising a hydraulic, pneumatic, mechanical or electronically driven piston that reduces the pressure applied to the roller.   The first motor of the wire feeder is connected to the first motorized grooved roller to rotate the first motorized grooved roller according to any one of claims 1-13. Metal wire feeding system as described.   The second motor of the slack wire tensioning device is connected to the second motorized grooved roller to rotate the second motorized grooved roller according to any one of claims 1-14. Metal wire feeding system as described.   The metal wire feeding system according to any one of claims 1 to 15, wherein the first motor of the wire feeding device operates independently of the slack wire pulling device.   The metal wire feeding system according to claim 1, wherein the housing further includes a loop detection device. The loop detection device is
a) a first sensor in communication with the control system, wherein the control system is configured to stop operation of the wire delivery system and the deposition process when the first sensor detects the loop of slack wire. A first sensor that transmits a signal, or b) a second sensor that communicates with a control system, wherein more metal wire is placed in the housing when the second sensor detects the loop of slack wires. A second sensor that sends a signal to the control system to deliver, or c) a third sensor that communicates with the control system when the third sensor detects the loop of slack wires A third sensor that sends a signal to the control system to deliver less metal wire into the housing, or d) a fourth sensor that communicates with the control system A fourth sensor for sending a signal to the control system to stop feeding the metal wire into the housing when the fourth sensor detects the loop of slack wire, or e ) Comprising any combination of a), b), c) and d),
The metal wire feeding system according to claim 17. A method of providing a metal wire to a welding torch, comprising:
Advancing a sufficient amount of the metal wire from a wire source to form a loop of slack wire;
Advancing a quantity of slack wire from said loop of slack wire to the plasma arc of the welding torch;
Supplying additional metal wire from the wire source to compensate for the amount of slack wire advanced to the welding torch to maintain a slack wire loop.   20. The method of claim 19, wherein the amount of slack wire advanced from the wire source is sufficient to maintain the loop of slack wire to allow continuous delivery of the slack wire to the welding torch. .   The wire source is an adjustable spool on which the metal wire is wound, and the method provides the metal wire to provide the metal wire to be advanced to form the loop of slack wire. 21. A method according to any one of claims 19 to 20, further comprising paying out from the spool.   Relocating the wire supply spool in at least one of the X direction, the Y direction, the Z direction, or a combination thereof in order to maintain the wire fed from the wire supply spool at a desired position. The method of claim 21, further comprising:   23. The method of any one of claims 19-22, further comprising rotating a roller in frictional contact with the metal wire to advance the metal wire into the housing.   24. The method of claim 23, wherein rotation of the roller is achieved by operating a motor attached to the roller, and the motor is a stepping motor or a direct current motor driven by an output control signal. .   25. A method according to any one of claims 19 to 24, wherein the advancement of the metal wire from the source is unaffected by the advancement of a certain amount of slack wire from the loop of slack wire to the welding torch. .   26. The method of any of claims 19-25, further comprising rotating a roller in frictional contact with the slack wire to deliver the slack wire to the welding torch.   27. The method of claim 26, wherein rotation of the roller is accomplished by operating a motor attached to the roller, and the motor is a stepping motor or a direct current motor driven by an output control signal. .   The welding torch is a plasma arc welding torch, a plasma transfer arc torch, a gas tungsten arc welding torch, a gas metal arc welding torch, a metal inert gas welding torch, a metal active gas welding torch, a laser device, an electron beam gun, or these 28. A method according to any one of claims 19 to 27, selected from any combination of:

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